Hey Delta,
I generally like the detail you have gone into on this map but I can see some areas that could really improve this map. The lighting is very strange, you have quite a dark sky yet in most places your terrain is quite bright, and that light is white. Such as in your first screenshot there are areas which are well lit but I cant see anything that lights them, apart from some smaller lights that couldnt light such a small area. The main light that is lighting the terrain should be darker and coloured, I suggest a dark blue to reflect the sky.
You have obvisously used fog to mask the end of the map but that doesnt feel right, I suggest you add some terrain to a SkyBox to make this battlefield feel bigger. Your woodplanks used in the terrain feel to bright and clean to be in that battlefield. The grass seems to be very rare and when there is some it is extremely dense/thick.
Some of your rooms feel a little too clutered with radom junk and objects that make the room feal crowded. Some of the holes in the walls just feel wrong, Some of the bunkers are not lit at all, atleast have somthing like a fire burning. Some of the staticmeshes are not lit.
Hope this all helps